JP6717156B2 - Transport system - Google Patents

Description

The present invention relates to a transfer system including a plurality of transfer vehicles.

For example, the transport system disclosed in Patent Document 1 below is configured such that a plurality of transport vehicles travel along a travel route. Then, this transport system detects the distance between the preceding transport vehicle traveling in front and the subsequent transport vehicle traveling behind the preceding transport vehicle by an optical distance sensor provided in the subsequent transport vehicle.

Japanese Patent No. 5071695

In a transport system including a plurality of transport vehicles, it is generally performed to maintain an appropriate inter-vehicle distance in order to avoid collision between the transport vehicles. In the transport system disclosed in Patent Document 1, for example, when the preceding transport vehicle and the following transport vehicle start from a state in which they are stopped, the preceding transport vehicle starts and then gradually opens. When the optical distance sensor detects that the inter-vehicle distance has become an appropriate inter-vehicle distance, the succeeding vehicle starts moving. However, in this configuration, since there is a time difference between the start of the preceding guided vehicle and the start of the following guided vehicle, the start of the succeeding guided vehicle is delayed compared to the start of the preceding guided vehicle, and the preceding guided vehicle and the succeeding guided vehicle are delayed. The distance between vehicles and the vehicle will be larger than necessary. As a result, the number of transport vehicles per unit distance on the transport route is reduced, and the transport efficiency of the entire system is reduced. This problem becomes particularly noticeable when a large number of transport vehicles are continuously running on the travel route.

Therefore, it is desired to realize a transportation system that can suppress the delay in starting the transportation vehicle and improve the transportation efficiency.

In view of the above, a characteristic configuration of a transport system including a plurality of transport vehicles is that each of the plurality of transport vehicles detects a distance from a preceding transport vehicle that is another transport vehicle traveling ahead. And a signal transmission unit capable of transmitting a start signal toward a subsequent conveyance vehicle that is another conveyance vehicle traveling behind, and a signal reception unit capable of receiving the start signal transmitted from the preceding conveyance vehicle. Each of the plurality of transport vehicles transmits the start signal by the signal transmitting unit at the start of traveling, and each of the plurality of transport vehicles transmits the start signal from the preceding transport vehicle by the signal receiving unit. Is received as one of the conditions for starting the vehicle, the vehicle starts at a set timing, and stops when the distance to the preceding transport vehicle detected by the distance detecting section becomes equal to or less than a set distance. ..

According to this configuration, the succeeding vehicle starts by receiving the start signal transmitted when the preceding vehicle starts traveling. Thereby, the time difference between the start of the preceding guided vehicle and the start of the succeeding guided vehicle can be shortened. Therefore, according to this configuration, it is possible to prevent the inter-vehicle distance from unnecessarily increasing, and it is possible to improve the transport efficiency. Also, when the distance detection unit detects that the distance from the preceding transport vehicle has become less than or equal to the set distance while the following transport vehicle is traveling, the subsequent transport vehicle stops, so The collision of can be appropriately avoided.

Further features and advantages of the technology according to the present disclosure will become more apparent by the following description of the exemplary and non-limiting embodiments described with reference to the drawings.

The whole top view of a conveyance system. The side view of a carrier vehicle. The block diagram which shows a control structure. The flowchart which shows the procedure of control in 1st embodiment. The schematic diagram which shows the movement of a conveyance vehicle. The flowchart which shows the procedure of control in 2nd embodiment.

1. First embodiment 1-1. Mechanical Configuration of Transport System A first embodiment of the transport system will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the transport system 1 includes a plurality of transport vehicles 2. For example, the transport vehicle 2 transports the article W to the transport target location 98. In this embodiment, the article W is a container in which a semiconductor substrate is stored. Further, the transfer target place 98 includes a processing device 98 a that processes the semiconductor substrate and a transfer unit 98 b that transfers the article W to and from the transfer vehicle 2. In this example, a plurality of such transfer target places 98 are provided. For example, the transport vehicle 2 may transport the article W to and from each of the plurality of transport target locations 98. More specifically, the article W may be received from one of the plurality of transportation target locations 98 and transported to the other transportation target location 98.

In the present embodiment, the transport vehicle 2 is a ceiling transport vehicle that travels on a rail 99 provided along the ceiling surface. The rail 99 is provided along a transport path that passes through a plurality of transport target locations 98. The transport vehicle 2 can transport the article W to each of the plurality of transport target locations 98 by traveling on the rail 99 along the transport path. Although detailed illustration is omitted, the transport path is configured to include a straight path, a curved path, a branch path, a confluent path, and the like, and, for example, may be configured to include an in-process path and an inter-process path. good. In this case, the plurality of transfer target places 98 are connected by the in-process route, and the plurality of in-process routes are connected by the inter-process route. The transport vehicle 2 can move to each of a plurality of intra-process paths connected by an inter-process path, and can move to each of a plurality of transfer target locations 98 connected by an intra-process path. In the present embodiment, the transport vehicle 2 can move along the transport path in only one direction and cannot move in the opposite direction.

The transport vehicle 2 can move between the plurality of transport target locations 98 and transfer the articles W to and from the transfer parts 98b corresponding to the plurality of transport target locations 98, respectively. In the present embodiment, the plurality of transfer units 98b are arranged below the transport vehicle 2. Further, as shown in FIG. 1, the plurality of transfer parts 98b are arranged so as to overlap the rail 99 in a plan view.

In the present embodiment, the transport vehicle 2 has a traveling unit 21 that travels along the rail 99. For example, the traveling unit 21 is arranged above the rail 99. In this example, the traveling unit 21 has traveling wheels 21a that are driven by the traveling motor 21m to rotate about the horizontal axis and roll on the upper surface of the rail 99 along the transport direction (see also FIG. 3). .. For example, the transport vehicle 2 includes a vehicle speed detection unit 21s that can detect the traveling speed of the transport vehicle 2 (see FIG. 3). For example, the vehicle speed detection unit 21s is configured to be able to detect the speed of the transport vehicle 2 based on the number of rotations of the traveling wheels 21a within a predetermined time, the relative speed to the rail 99, and the like.

In the present embodiment, the transport vehicle 2 has a main body portion 22 suspended and supported by the traveling portion 21. For example, the main body 22 is arranged below the rail 99. The main body portion 22 is connected to the traveling portion 21, and the traveling of the traveling portion 21 causes the rail 99 to move integrally with the traveling portion 21. In this example, the main body portion 22 has a storage portion 22a that stores the article W. In the present embodiment, the main body 22 is formed in a gate shape in which both sides and the lower side in a direction (hereinafter, lateral direction) orthogonal to the transport direction in the horizontal plane are open. More specifically, the accommodating portion 22a is formed in an inverted U-shape that is angular when viewed in the lateral direction. In the present embodiment, the transport vehicle 2 transfers the article W between the transfer section 98b and the storage section 22a.

In this embodiment, the transport vehicle 2 includes a transfer device 23 that transfers the article W to and from the transfer unit 98b. For example, the transfer device 23 is arranged inside the housing portion 22a. In this example, the transfer device 23 has a gripping mechanism 24 for gripping the article W and an elevating mechanism 25 for elevating the article W. Note that, for example, the transfer device 23 may have a swivel mechanism or the like for adjusting the posture of the article to a proper posture at the destination.

The gripping mechanism 24 can grip the article W. For example, the gripping mechanism 24 grips the article W from above. More specifically, the gripping mechanism 24 grips the article W from above in a state of overlapping the article W in a plan view. In the present embodiment, the gripping mechanism 24 has a pair of gripping claws 24a that are driven by a gripping motor 24m and are switchable between a gripping posture and a releasing posture. Then, the pair of gripping claws 24a are brought into a gripping posture by moving in a direction approaching each other, and are brought into a releasing posture by moving in a direction separating from each other. In the present embodiment, the pair of grip claws 24a grips the article W in the grip posture. Then, the pair of gripping claws 24a release the grip of the article W by taking the release posture from the state of gripping the article W. For example, the grip mechanism 24 includes a grip detection unit 24s that detects the grip posture and the release posture of the pair of grip claws 24a (see FIG. 3 ). For example, the grip detection unit 24s is configured to be able to detect whether the pair of grip claws 24a is in the grip posture or the release posture, based on whether or not the optical axis is blocked by the pair of grip claws 24a.

The elevating mechanism 25 can elevate and lower the article W. In the present embodiment, the lifting mechanism 25 includes a lifting platform 25a, a lifting pulley (not shown) around which a lifting belt 25b is wound, and a lifting motor 25m (see FIG. 3) that drives the lifting pulley. There is. Then, the elevating mechanism 25 drives the elevating pulley by the elevating motor 25m to reel out and wind up the elevating belt 25b, and can elevate the elevating table 25a connected to the elevating belt 25b. In this example, the lifting table 25a is connected to the gripping mechanism 24. Accordingly, the lifting mechanism 25 can lift the article W gripped by the gripping mechanism 24. The elevating mechanism 25 can elevate and lower the article W at least between the height at which the transport vehicle 2 is disposed and the height at which the transfer unit 98b of the transport target location 98 is disposed. For example, the lifting mechanism 25 includes a lifting amount detector 25s that detects the lifting amount of the lifting platform 25a (see FIG. 3). For example, the ascending/descending amount detection unit 25s is configured to be able to detect the ascending/descending amount of the ascending/descending table 25a based on the number of rotations of the ascending/descending pulley when the ascending/descending table 25a is ascended/descended, the time during which the ascending/descending pulley rotates, and the like.

As described above, the transport system 1 includes the plurality of transport vehicles 2, and each of the plurality of transport vehicles 2 transports the article W in the same transport path. In the present embodiment, each of the plurality of transport vehicles 2 has a distance detection unit 22s that detects the actual distance D from the preceding transport vehicle 2F, which is another transport vehicle 2 traveling ahead. For example, the distance detection unit 22s is arranged on either the traveling unit 21 or the main body unit 22 of the transport vehicle 2. In the present embodiment, the distance detection unit 22s is arranged in the main body 22 of the transport vehicle 2. More specifically, the distance detecting unit 22s is configured by an optical axis sensor including a light projecting unit 22sa that projects light and a reflecting plate 22sb that reflects the light projected from the light projecting unit 22sa. The light projecting unit 22sa is arranged on the front side in the carrying direction of the housing 22a, and the reflector 22sb is arranged on the rear side of the housing 22a in the carrying direction. In the present embodiment, the light projecting unit 22sa projects light toward the reflecting plate 22sb of the preceding transport vehicle 2F, and the light projecting unit 22sa receives the light reflected by the reflecting plate 22sb so that the light is transported. The actual distance D between the vehicle 2 and the preceding transport vehicle 2F traveling in front of the transport vehicle 2 is detected. In other words, the actual distance D between the two guided vehicles 2 is detected by the succeeding guided vehicle 2R traveling behind them.

Here, conventionally, the conditions under which the succeeding transport vehicle 2R starts when the preceding transport vehicle 2F and the subsequent transport vehicle 2R are stopped are as follows. That is, the condition for starting the succeeding transport vehicle 2R was that the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R was equal to or greater than the set distance. The set distance here is set to, for example, a safe inter-vehicle distance in which the possibility of collision between the preceding transport vehicle 2F and the subsequent transport vehicle 2R is low even when the following transport vehicle 2R travels. Conventionally, the preceding transport vehicle 2F starts, and after the distance detection unit 22s detects that the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R has reached the set distance, the subsequent transport vehicle 2R It was supposed to start. Therefore, there is a time difference in starting between the preceding transport vehicle 2F and the following transport vehicle 2R, and the subsequent transport vehicle 2R has started after the start of the preceding transport vehicle 2F. As a result, the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R becomes unnecessarily large, which in turn lowers the transport efficiency.

Therefore, in the present embodiment, each of the plurality of transport vehicles 2 has a signal transmission unit 27y capable of transmitting the start signal SI toward the succeeding transport vehicle 2R, which is another transport vehicle 2 traveling rearward, and the preceding transport vehicle 2. And a signal receiving section 27x capable of receiving the start signal SI transmitted from 2F (see FIG. 3). Then, each of the plurality of transport vehicles 2 starts when the signal reception unit 27x receives the start signal SI from the preceding transport vehicle 2F. In other words, in the present embodiment, the reception of the start signal SI by the succeeding vehicle 2R is one of the conditions for starting the succeeding vehicle 2R. By setting the reception of the start signal SI as one of the start conditions, it is possible to adjust the start timing of the succeeding guided vehicle 2R. For example, the succeeding vehicle 2R may be started at the same time as the reception of the start signal SI, or the succeeding vehicle 2R may be started after a set time has elapsed after receiving the start signal SI. That is, after the succeeding vehicle 2R receives the start signal SI, the succeeding vehicle 2R can be started by adjusting to the best timing, so that the actual distance D between the preceding vehicle 2F and the succeeding vehicle 2R can be adjusted. Can be prevented from becoming larger than necessary. Therefore, according to this configuration, the transfer efficiency of the transfer system 1 can be improved.

In the present embodiment, each of the plurality of transport vehicles 2 transmits the start signal SI by the signal transmission unit 27y at the start of traveling. More specifically, the preceding transport vehicle 2F transmits a start signal SI to the signal receiving unit 27x of the subsequent transport vehicle 2R at the start of traveling. For example, the preceding conveyance vehicle 2F starts transmitting the start signal SI at the start of traveling and continuously transmits the start signal SI during traveling. In this case, the signal receiving unit 27x of the succeeding transport vehicle 2R receives the start signal SI simultaneously with the start of the traveling of the preceding transport vehicle 2F and continuously receives the start signal SI while the preceding transport vehicle 2F is traveling.

1-2. Control Configuration of Transport System The control configuration of the transport system 1 will be described below with reference to FIG.
The transport system 1 includes a control device H. The control device H is configured to include an integrated control device Ht that controls the entire transport system 1 and an individual control device Hm that controls the transport vehicle 2. The individual control device Hm is provided in each of the plurality of transport vehicles 2 and controls each of the plurality of transport vehicles 2. The integrated control device Ht controls the entire transport system 1 including the plurality of individual control devices Hm. For example, the control device H includes a processor such as a microcomputer and peripheral circuits such as a memory. Each function of the control device H is realized by the cooperation of these hardware and a program executed on a processor such as a computer.

In the present embodiment, the overall control device Ht and each of the plurality of individual control devices Hm can communicate with each other. For example, in order to move the transport vehicle 2 to the transport target location 98 or the like, the overall control device Ht issues a command to the individual control device Hm corresponding to the transport vehicle 2. Then, the individual control device Hm that has received the command controls the operation of the transport vehicle 2 so that the transport vehicle 2 can be moved to the transport target location 98 or the like.

In the present embodiment, the individual control device Hm acquires various information detected by the vehicle speed detection unit 21s, the distance detection unit 22s, the grip detection unit 24s, and the lift amount detection unit 25s, and travels based on these information. The operation of the motor 21m, the gripping motor 24m, and the lifting motor 25m is controlled.

In the present embodiment, the individual control device Hm controls the operation of the signal transmission unit 27y. More specifically, when the individual control device Hm of the preceding transport vehicle 2F receives a command from the overall control device Ht and starts the preceding transport vehicle 2F, the individual control device Hm controls the signal transmitting unit 27y to control the following transport vehicle 2R. The start signal SI is transmitted to the signal receiving unit 27x. Further, the individual control device Hm of the succeeding transport vehicle 2R receives the start signal SI transmitted from the signal transmitting unit 27y of the preceding transport vehicle 2F by the signal receiving unit 27x.

In the present embodiment, each of the plurality of transport vehicles 2 has a start determination unit 27j that determines whether or not the transport vehicle 2 can be started. Then, the individual control device Hm starts the transport vehicle 2 based on the determination result of the start determination unit 27j. More specifically, when the signal receiving unit 27x receives the start signal SI from the preceding transport vehicle 2F and the start determination unit 27j determines that the following transport vehicle 2R may be started. The individual control device Hm of the subsequent transport vehicle 2R starts the subsequent transport vehicle 2R. For example, the start determination unit 27j of the succeeding guided vehicle 2R determines that it is possible to start at the same time as the start signal SI is received by the signal reception unit 27x. In addition, for example, the start determination unit 27j of the subsequent transport vehicle 2R, based on the actual distance D from the preceding transport vehicle 2F detected by the distance detection unit 22s in a state where the signal reception unit 27x receives the start signal SI, Determine whether to start. In addition, for example, the start determination unit 27j of the succeeding guided vehicle 2R determines whether or not the vehicle can be started based on the elapsed time from the time when the start signal SI is received by the signal reception unit 27x.

1-3. Control of Transport System Next, control of the transport system 1 will be described with reference to FIG. FIG. 4 is a flowchart showing a procedure of controlling the succeeding transportation vehicle 2R. Note that “=” in FIG. 4 is an assignment operator, which means that the value on the right side is assigned to the left side. “==” is a comparison operator and means that the left side and the right side are equivalent.

The individual control device Hm of the succeeding transport vehicle 2R determines whether or not the succeeding transport vehicle 2R is in the stopped state (#100). When it is determined that the succeeding vehicle 2R is in the stopped state (#100: Yes), it is determined whether or not the start signal SI is received by the signal receiving unit 27x (#101). As described above, the start signal SI is transmitted by the signal transmitter 27y of the preceding transport vehicle 2F when the traveling of the preceding transport vehicle 2F is started. In the present embodiment, the preceding transport vehicle 2F travels at a normal speed (Normal) after starting.

When the individual control device Hm of the succeeding transport vehicle 2R determines that the start signal SI is received by the signal receiving unit 27x (#101: Yes), the actual distance D from the preceding transport vehicle 2F is the first set distance TH1. It is determined whether or not it is less than (#102). Here, the first set distance TH1 is an arbitrarily set distance. In the present embodiment, the first set distance TH1 is set to a distance required from the state where the succeeding transport vehicle 2R is traveling at the maximum speed of the estimated usable speed to the stop. The first set distance TH1 may be set experimentally according to various situations. For example, when a large number of transport vehicles 2 travel on the transport route, or when the transport vehicles 2 travel on a curved road, the traveling speed of the transport vehicle 2 also slows down. In this case, therefore, the first set distance TH1 Is set to a small value. Further, for example, when a small number of transport vehicles 2 travel on the transport route or when the transport vehicles 2 travel on a straight road, the traveling speed of the transport vehicle 2 can be increased. The distance TH1 is set to a large value. Further, for example, the first set distance TH1 may be set separately depending on whether the transport vehicle 2 travels on the inter-process route or on the intra-process route. For example, the first set distance TH1 may be set long for a relatively wide inter-process route, and the first set distance TH1 may be set short for a relatively narrow in-process route. The first set distance TH1 may be a variable value that changes according to other various parameters. The first set distance TH1 corresponds to the “set distance”.

In the present embodiment, when the actual distance D to the preceding transport vehicle 2F is less than the first set distance TH1, each of the plurality of transport vehicles 2 is connected to the preceding transport vehicle 2F detected by the distance detecting unit 22s. Does not stop even if the actual distance D is less than the first set distance TH1 and is lower than the traveling speed of the preceding transport vehicle 2F until the actual distance D with the preceding transport vehicle 2F becomes longer than the first set distance TH1. To run. More specifically, as shown in FIG. 4, when the individual control device Hm of the succeeding transport vehicle 2R determines that the actual distance D from the preceding transport vehicle 2F is less than the first set distance TH1 (#102). : Yes), the target speed Vt of the succeeding vehicle 2R is set to a low speed (Slow) (#103). As a result, the succeeding vehicle 2R starts at a low speed (Slow), and the actual distance D from the preceding vehicle 2F traveling at the normal speed (Normal) gradually increases. Then, the succeeding transportation vehicle 2R travels at a low speed (Slow) until the actual distance D from the preceding transportation vehicle 2F becomes longer than the first set distance TH1. The traveling speed at low speed (Slow) is set to be lower than the normal speed (Normal). The traveling speed at low speed (Slow) may be set experimentally. For example, the traveling speed at low speed (Slow) is set to 50 to 80% of the normal speed (Normal).

When the individual control device Hm of the succeeding carrier 2R determines that the actual distance D from the preceding carrier 2F is not less than the first set distance TH1 (#102: No), the target speed Vt of the succeeding carrier 2R is normally set. Set to speed (Normal). As a result, the succeeding vehicle 2R starts at the normal speed (Normal) that is the same as the speed of the preceding vehicle 2F. As described above, in the present embodiment, in each of the plurality of transport vehicles 2, the actual distance D to the preceding transport vehicle 2F detected by the distance detection unit 22s is longer than the first set distance TH1 during traveling. Adjust the running speed so that

The individual control device Hm of the succeeding transport vehicle 2R sets the target speed Vt of the succeeding transport vehicle 2R to either the low speed (Slow) or the normal speed (Normal), and after the subsequent transport vehicle 2R has started, the preceding transport operation is performed. It is determined whether or not the actual distance D to the vehicle 2F is less than the second set distance TH2 (#105). Here, the second set distance TH2 is a distance that is arbitrarily set. For example, the second set distance TH2 is a distance obtained by adding the additional distance calculated in consideration of hunting prevention, control delay, etc. to the first set distance TH1. Similarly to the first set distance TH1, the second set distance TH2 may be set experimentally in accordance with various situations such as the number of traveling guided vehicles 2 and traveling places. The second set distance TH2 may be a variable value that changes according to various parameters.

When the individual control device Hm of the subsequent transport vehicle 2R determines that the actual distance D from the preceding transport vehicle 2F is less than the second set distance TH2 (#105: Yes), the target speed Vt of the subsequent transport vehicle 2R is set. It is set to a low speed (Slow) (#106). In other words, the traveling speed of the succeeding guided vehicle 2R is adjusted so that the actual distance D from the preceding guided vehicle 2F becomes the second set distance TH2.

In the present embodiment, each of the plurality of transport vehicles 2 stops when the actual distance D from the preceding transport vehicle 2F detected by the distance detection unit 22s becomes equal to or less than the first set distance TH1. More specifically, as shown in FIG. 4, after step 106 (#106), the individual control device Hm of the succeeding transport vehicle 2R determines that the actual distance D from the preceding transport vehicle 2F is less than the first set distance TH1. It is determined whether there is any (#107). When it is determined that the actual distance D to the preceding transport vehicle 2F is less than the first set distance TH1 (#107: Yes), the target speed Vt of the subsequent transport vehicle 2R is set to zero (#108). As a result, the succeeding transportation vehicle 2R is stopped. For example, if the succeeding transport vehicle 2R is running when the preceding transport vehicle 2F is stopped due to traffic jam, transfer of the article W, equipment failure, or the like, the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R is Becomes less than the first set distance TH1 and step 108 (#108) is executed as described above. When the individual control device Hm of the succeeding transport vehicle 2R determines that the actual distance D from the preceding transport vehicle 2F is not less than the first set distance TH1 (#107: No), step 105 is executed again (#105). ..

When the individual control device Hm of the succeeding carrier 2R determines that the actual distance D from the preceding carrier 2F is not less than the second set distance TH2 (#105: No), the target speed Vt of the succeeding carrier 2R is normally set. The speed is set to Normal (#109). In other words, when the actual distance D to the preceding conveyance vehicle 2F becomes equal to or larger than the second set distance TH2, the succeeding conveyance vehicle 2R is caused to travel at the normal speed (Normal) which is the same speed as the preceding conveyance vehicle 2F. This can prevent the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R from increasing more than necessary.

Here, in the above, when the actual distance D to the preceding transport vehicle 2F is less than the second set distance TH2, it is determined whether the actual distance D to the preceding transport vehicle 2F is less than the first set distance TH1. (#107), if this determination is a positive determination (#107: Yes), the target speed Vt of the succeeding guided vehicle 2R has been set to zero (#108). However, even when the distance detection unit 22s determines that the actual distance D to the preceding transport vehicle 2F is equal to or greater than the second set distance TH2, the vicinity of the curved path, the branch path, or the confluent path on the transport path. Then, the presence of the preceding transport vehicle 2F may be detected within the range less than the first set distance TH1 in front of the following transport vehicle 2R due to the detection performance of the distance detection unit 22s, interruption of another preceding transport vehicle 2F, or the like. .. In that case, the preceding transport vehicle 2F and the subsequent transport vehicle 2R may collide. Therefore, as shown in FIG. 4, the individual control device Hm of the succeeding vehicle 2R is in a state where the actual distance D from the preceding vehicle 2F is equal to or greater than the second set distance TH2 and the succeeding vehicle 2R has the normal speed ( While traveling in Normal (#109), it is determined whether the actual distance D to the preceding transport vehicle 2F is less than the first set distance TH1 (#110). When it is determined that the actual distance D from the preceding transport vehicle 2F is less than the first set distance TH1 (#110: Yes), the target speed Vt of the subsequent transport vehicle 2R is set to zero (#111).

The individual control device Hm of the succeeding transport vehicle 2R sets the actual distance D to the preceding transport vehicle 2F at the first set distance after performing step 108 (#108), after performing step 111 (#111), and at step 110. When it is determined that it is not less than TH1 (#110: No), it is determined whether or not the succeeding guided vehicle 2R has reached the target location instructed by the overall control device Ht (#112). When it is determined that the succeeding vehicle 2R has not reached the target location (#112: No), step 100 is executed again (#100). Here, if it is determined that the succeeding guided vehicle 2R has not reached the target location after execution of step 108 (#108) and after execution of step 111 (#111) (#112: No), Since the succeeding transportation vehicle 2R is stopped, a positive determination is made in step 100 (#100: Yes). On the other hand, when it is determined in step 110 that the actual distance D from the preceding transport vehicle 2F is not less than the first set distance TH1 (#110: No), it is determined that the subsequent transport vehicle 2R has not reached the target location. (#112: No), the succeeding transport vehicle 2R is in a traveling state, so a negative determination is made in step 100 (#100: No). In this case, step 104 is then executed (#104). In addition, when a negative determination is made in step 101 (#101: No), it is determined in step 112 whether or not the succeeding guided vehicle 2R has reached the target location (#112).

Hereinafter, the movement of the carrier 2 will be briefly described with reference to FIG.
In the phase A1, the leading transport vehicle 2F and the following transport vehicle 2R are stopped at the actual distance D1(D). The actual distance D1 is longer than the first set distance TH1 and shorter than the second set distance TH2. Next, the preceding transport vehicle 2F receives a command from the overall control device Ht and starts moving, and at the same time, transmits a start signal SI to the following transport vehicle 2R. The succeeding vehicle 2R that has received the start signal SI starts moving and travels at a low speed (Slow) (phase A2). After that, the subsequent transport vehicle 2R travels at the normal speed (Normal) when the actual distance D2(D) from the preceding transport vehicle 2F becomes equal to or greater than the second set distance TH2 (Phase A3). The preceding transport vehicle 2F is stopped due to, for example, traffic jam, transfer of the article W, equipment failure, etc., and the actual distance D3 (D) between the preceding transport vehicle 2F and the subsequent transport vehicle 2R is less than the second set distance TH2. When it becomes, the succeeding transportation vehicle 2R travels at a low speed (Slow) (phase A4). Then, the succeeding transport vehicle 2R stops when the actual distance D from the preceding transport vehicle 2F becomes equal to or less than the first set distance TH1. For example, the succeeding transport vehicle 2R starts to stop when the actual distance D to the preceding transport vehicle 2F is the first set distance TH1, and the traveling vehicle slightly travels due to the inertia after that, and consequently the succeeding transport vehicle 2R stops. The actual distance D4(D) from the preceding transport vehicle 2F in the above state is shorter than the first set distance TH1 (phase A5).

Here, as described above, the succeeding transport vehicle 2R starts by receiving the start signal SI from the preceding transport vehicle 2F, and therefore, it starts at substantially the same time as the preceding transport vehicle 2F. On the other hand, when the preceding transport vehicle 2F is stopped, the subsequent transport vehicle 2R starts to stop, but travels a little due to the inertia thereafter. Therefore, after the trailing transport vehicle 2R has stopped after starting, the actual distance D from the leading transport vehicle 2F becomes shorter than that at the time of starting. When this operation is repeated, the actual distance D from the preceding transport vehicle 2F becomes shorter each time the subsequent transport vehicle 2R stops after starting, and there is a possibility that both will eventually collide. Therefore, in each of the plurality of transport vehicles 2, the signal receiving unit 27x receives the start signal SI and the actual distance D with the preceding transport vehicle 2F detected by the distance detecting unit 22s is greater than the first set distance TH1. You may start if it is long. More specifically, as shown in FIG. 5, even when the preceding transport vehicle 2F starts to move, the start signal SI is transmitted to the following transport vehicle 2R, and the subsequent transport vehicle 2R receives the start signal SI, When the actual distance D5(D) between the preceding transport vehicle 2F and the subsequent transport vehicle 2R is less than or equal to the first set distance TH1, the subsequent transport vehicle 2R is maintained in the stopped state (phase A6). Then, when the actual distance D6 (D) between the preceding transport vehicle 2F and the subsequent transport vehicle 2R becomes longer than the first set distance TH1, the subsequent transport vehicle 2R starts (phase A7). At this time, if the actual distance D6(D) to the preceding conveyance vehicle 2F is less than the second set distance TH2, the succeeding conveyance vehicle 2R may travel at a low speed (Slow) (phase A7).

2. Second Embodiment Next, a second embodiment of the transport system 1 will be described with reference to FIG. In the second embodiment, the control of the transport system 1 is different from that in the first embodiment. The second embodiment will be described below, focusing on the differences from the first embodiment. The points that are not particularly described are the same as those in the first embodiment.

2-1. Control of Transport System According to Second Embodiment As shown in FIG. 6, the individual control device Hm of the subsequent transport vehicle 2R determines whether or not the subsequent transport vehicle 2R is stopped (#200). When it is determined that the succeeding vehicle 2R is in the stopped state (#200: Yes), it is determined whether or not the start signal SI is received by the signal receiving unit 27x (#201). Here, in the second embodiment, in each of the plurality of transport vehicles 2, the actual distance D from the preceding transport vehicle 2F is less than the first set distance TH1, and the signal receiving unit 27x receives the start signal SI. The vehicle starts after the set time Ts has elapsed. More specifically, as shown in FIG. 6, when the individual control device Hm of the succeeding transport vehicle 2R determines that the start signal SI is received by the signal receiving unit 27x (#201: Yes), the timer is It is determined whether the set time Ts has passed (#202). When the timer determines that the set time Ts has elapsed (#202: Yes), the target speed Vt of the succeeding guided vehicle 2R is set to the normal speed (Normal) (#203). Here, the set time Ts is an arbitrarily set time. In the second embodiment, the set time Ts is set at the timing when the preceding transport vehicle 2F starts and the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R becomes longer than the first set distance TH1. The set time Ts may be experimentally set according to various situations such as the traveling speed of the preceding transport vehicle 2F. For example, when the preceding transport vehicle 2F travels at a relatively low speed, the set time Ts is set to a relatively long time. When the preceding transport vehicle 2F travels at a relatively high speed, the set time Ts is set to a relatively short time.

When the individual control device Hm of the succeeding transportation vehicle 2R determines that the timer has not elapsed the set time Ts (#202: No), step 202 is repeated. If it is not determined that the set time Ts has elapsed, step 202 may not be repeated and an error may be notified.

After setting the target speed Vt to the normal speed (Normal), the individual control device Hm of the succeeding transportation vehicle 2R executes any one of step 204 (#204) to step 211 (#211). As shown in FIG. 4, steps 204 (#204) to 211 (#211) in the second embodiment include steps 105 (#105) to 112 (#112) in the first embodiment. Since it is similar to the step, the description is omitted.

3. Other Embodiments Next, other embodiments of the transport system will be described.

(1) In the above embodiment, an example in which the transport vehicle 2 is controlled with two distances, the first set distance TH1 and the second set distance TH2, as threshold values has been described. However, the present invention is not limited to such an example. That is, the transport vehicle 2 may be configured to have three or more distances as thresholds. The more thresholds that serve as a guideline for control, the finer the control according to various situations becomes possible. On the contrary, the transport vehicle 2 may be configured to control only the first set distance TH1 as a threshold value. The smaller the threshold value that is a guideline for control, the simpler the control configuration can be.

(2) In the above embodiment, an example in which the first set distance TH1 and the second set distance TH2 are set as threshold values and the transport vehicle 2 is controlled based on these threshold values has been described. Specifically, in the above-described embodiment, while the subsequent transport vehicle 2R is traveling, the subsequent transport is performed such that the actual distance D with the preceding transport vehicle 2F is longer than the first set distance TH1 or the second set distance TH2. It was configured to adjust the traveling speed of the vehicle 2R in stages. However, the present invention is not limited to such an example. That is, the target distance Ds is set so that the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R becomes a desired value, and the subsequent transport vehicle 2R is feedback-controlled so that the actual distance D approaches the target distance Ds. It may be configured as follows. For example, a distance longer than the first set distance TH1 is set as the target distance Ds, and the succeeding guided vehicle 2R is controlled so that the actual distance D approaches the target distance Ds. As a result, the succeeding transport vehicle 2R can be safely driven while the actual distance D is maintained at a distance longer than the first set distance TH1.

(3) In the above embodiment, the preceding transport vehicle 2F is configured to start transmitting the start signal SI at the start of traveling and continuously transmit the start signal SI during traveling, and the subsequent transport vehicle 2R is The example has been described in which the start signal SI is received at the same time when the preceding transport vehicle 2F starts traveling and the start signal SI is continuously received during traveling of the preceding transport vehicle 2F. However, the present invention is not limited to such a configuration. That is, the preceding guided vehicle 2F may be configured to transmit the start signal SI only at the start of traveling. In this case, the individual control device Hm of the succeeding vehicle 2R may include a storage unit, and the storage unit may store the fact that the signal receiving unit 27x has received the start signal SI.

(4) In the above-described second embodiment, the example in which the set time Ts is set at the timing when the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R is longer than the first set distance TH1 has been described. However, the present invention is not limited to such an example. The set time Ts may be set at a timing at which the actual distance D between the preceding transport vehicle 2F and the subsequent transport vehicle 2R becomes longer than the second set distance TH2, or at various other timings. Is also good.

(5) In the above embodiment, an example in which the carrier 2 is a ceiling carrier that travels on a rail 99 provided along the ceiling surface has been described. However, the present invention is not limited to such an example. For example, the carrier 2 may be an unmanned carrier that travels on the floor.

4. Outline of the Embodiments The outline of the transport system described above will be described below.

A transport system including a plurality of transport vehicles, wherein each of the plurality of transport vehicles travels behind a distance detection unit that detects a distance from a preceding transport vehicle that is another transport vehicle traveling in front. A plurality of signal transmission units capable of transmitting a start signal toward a subsequent transport vehicle that is another transport vehicle, and a signal receiving unit capable of receiving the start signal transmitted from the preceding transport vehicle; each transport vehicle, the traveling start, and sends the start signal by the signal transmitting unit, each of the plurality of guided vehicles, starting of the reception of the start signal from the preceding transport car by the signal receiving section As one of the conditions of 1), the vehicle starts at a set timing and stops when the distance to the preceding transport vehicle detected by the distance detection unit becomes equal to or less than a set distance.

According to this configuration, the succeeding vehicle starts by receiving the start signal transmitted when the preceding vehicle starts traveling. Thereby, the time difference between the start of the preceding guided vehicle and the start of the succeeding guided vehicle can be shortened. Therefore, according to this configuration, it is possible to prevent the inter-vehicle distance from unnecessarily increasing, and it is possible to improve the transport efficiency. Also, when the distance detection unit detects that the distance from the preceding transport vehicle has become less than or equal to the set distance while the following transport vehicle is traveling, the subsequent transport vehicle stops, so The collision of can be appropriately avoided.

Further, in the above configuration, each of the plurality of transport vehicles adjusts a traveling speed such that a distance from the preceding transport vehicle detected by the distance detection unit during traveling is longer than the set distance. It is preferable to do so.

While the preceding transport vehicle and the subsequent transport vehicle are traveling, for example, when the traveling speed of the preceding transport vehicle becomes slow due to a malfunction of the device, the inter-vehicle distance between the preceding transport vehicle and the subsequent transport vehicle becomes gradually shorter, Eventually, the two may collide. Even in such a case, according to this configuration, the succeeding transport vehicle adjusts the traveling speed so that the distance to the preceding transport vehicle detected by the distance detecting unit becomes longer than the set distance, and thus the traveling speed is reduced. It is possible to avoid a collision between the preceding transport vehicle and the subsequent transport vehicle inside.

Further, in each of the plurality of transport vehicles, when the distance to the preceding transport vehicle is set to be less than the set distance, the distance to the preceding transport vehicle detected by the distance detection unit is equal to or less than the set distance. However, it is preferable that the vehicle does not stop and travels at a speed lower than the traveling speed of the preceding transport vehicle until the distance to the preceding transport vehicle becomes longer than the set distance.

For example, when both the preceding transport vehicle and the subsequent transport vehicle are stopped at a short inter-vehicle distance that is less than the set distance, when both start at the same time, both of them will start traveling with the short inter-vehicle distance. According to this configuration, the succeeding transport vehicle travels at a speed lower than the traveling speed of the preceding transport vehicle until the distance from the preceding transport vehicle becomes longer than the set distance. It is possible to bring the inter-vehicle distance into an appropriate state within a certain period while suppressing the above.

Further, in each of the plurality of transport vehicles, when the signal receiving unit receives the start signal and the distance from the preceding transport vehicle detected by the distance detecting unit is longer than the set distance. It is preferable to start at.

According to this configuration, for example, the signal receiving unit of the succeeding transport vehicle is transmitted from the signal transmitting unit of the preceding transport vehicle in a state where the preceding transport vehicle and the subsequent transport vehicle are stopped at an inter-vehicle distance shorter than the set distance. Even when the start signal is received, the start of the succeeding guided vehicle at the time of the reception can be restricted. Then, when the signal receiving unit of the succeeding vehicle receives the start signal and the inter-vehicle distance detected by the distance detecting unit becomes longer than the set distance, the succeeding vehicle starts. With such a configuration, the succeeding vehicle prepares to start when the start signal is received, and can immediately start when the inter-vehicle distance from the preceding vehicle becomes longer than the set distance. Therefore, according to this configuration, it is possible to start the succeeding vehicle without delay, and it is possible to maintain an appropriate inter-vehicle distance while suppressing an increase in the inter-vehicle distance due to the delay in starting the succeeding vehicle.
Further, in the above configuration, it is preferable that each of the plurality of transport vehicles starts at the same time as the reception of the start signal when the distance to the preceding transport vehicle detected by the distance detection unit is longer than the set distance. is there.

Further, it is preferable that each of the plurality of transport vehicles has a distance from the preceding transport vehicle less than the set distance, and the signal receiving unit receives the start signal and starts the vehicle after a set time has elapsed.

According to this configuration, for example, the signal receiving unit of the succeeding transport vehicle is transmitted by the signal transmitting unit of the preceding transport vehicle in a state where the preceding transport vehicle and the subsequent transport vehicle are stopped at an inter-vehicle distance shorter than the set distance. Even when the start signal is received, the start of the succeeding guided vehicle at the time of the reception can be restricted. Since the succeeding vehicle starts after the set time has elapsed after receiving the start signal, the preceding vehicle is already traveling at the time when the succeeding vehicle starts. Therefore, it is possible to maintain a safe distance between the preceding guided vehicle and the preceding guided vehicle when the succeeding guided vehicle starts. Further, the set time is, for example, experimentally determined, and can be adjusted so that the succeeding vehicle starts at the best timing, and the delay in starting the succeeding vehicle can be suppressed. Therefore, according to this configuration, an appropriate inter-vehicle distance can be maintained while suppressing an increase in inter-vehicle distance due to a delay in the start of the succeeding vehicle.

The technology according to the present disclosure can be used for a transport system including a plurality of transport vehicles.

1: Transport system 2: Transport vehicle 2F: Leading transport vehicle 2R: Subsequent transport vehicle 22s: Distance detection unit 27x: Signal receiving unit 27y: Signal transmitting unit D: Actual distance SI: Start signal TH1: First set distance Ts: Setting time

Claims (6)

A transport system including a plurality of transport vehicles,
Each of the plurality of transport vehicles starts toward a distance detection unit that detects a distance from a preceding transport vehicle that is another transport vehicle that travels in the front and a trailing transport vehicle that is another transport vehicle that travels in the rear. A signal transmitting unit capable of transmitting a signal, and a signal receiving unit capable of receiving the start signal transmitted from the preceding transport vehicle,
Each of the plurality of transport vehicles transmits the start signal by the signal transmitting unit at the start of traveling,
Each of the plurality of guided vehicles starts at a set timing with one of the conditions for starting when the signal receiving unit receives the start signal from the preceding guided vehicle , and is detected by the distance detection unit. A transport system that stops when the distance to the preceding transport vehicle becomes less than or equal to a set distance. The traveling speed of each of the plurality of transport vehicles is adjusted such that a distance from the preceding transport vehicle detected by the distance detection unit is longer than the set distance during traveling. Transport system. In each of the plurality of transport vehicles, when the distance to the preceding transport vehicle is less than the set distance, the distance to the preceding transport vehicle detected by the distance detection unit is equal to or less than the set distance. The transport system according to claim 1 or 2, wherein the transport system does not stop, and travels at a speed lower than the traveling speed of the preceding transport vehicle until the distance to the preceding transport vehicle becomes longer than the set distance. Each of the plurality of transport vehicles starts when the signal receiving unit receives the start signal and the distance from the preceding transport vehicle detected by the distance detection unit is longer than the set distance. Item 2. The transport system according to Item 1 or 2. The transport system according to claim 4, wherein each of the plurality of transport vehicles starts at the same time as the reception of the start signal when the distance from the preceding transport vehicle detected by the distance detection unit is longer than the set distance. .. The distance of each of the plurality of transport vehicles from the preceding transport vehicle is less than the set distance, and the signal receiving unit receives the start signal and starts after a set time has elapsed. Transport system.

Images